Cycloaddition catalysts, their preparation methods and applications; methods for preparing cyclic carbonates.

Abstract

This invention relates to the field of catalysts, and discloses a cycloaddition catalyst, its preparation method and application, and a method for preparing cyclic carbonates. The catalyst contains a support formed by a shaped molecular sieve and an ion exchange resin supported on the support. The catalyst has the structure shown in formula (1), where is the support, is a styrene copolymer segment, R1 is an alkyl or aryl group, and X... ‑ It is an anion. The cycloaddition catalyst of the present invention is a heterogeneous catalyst with high strength, easy separation after use, high catalytic activity, and high stability. The catalyst can be used continuously multiple times. For example, when used as a cycloaddition catalyst, it can yield a high yield of cycloaddition product, and even after the catalyst is recycled multiple times, a high yield of cycloaddition product can still be obtained.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, specifically to a cycloaddition catalyst, its preparation method and application, and a method for preparing cyclic carbonates. Background Technology

[0002] The new energy industry is a key emerging industry for national development, and the development of new energy vehicles has led to increasing attention being paid to the application of power batteries. As an important component of power batteries, the demand for alkylene carbonate solvents such as ethylene carbonate and propylene carbonate is also increasing year by year. In addition, alkylene carbonates also have important applications in printing, polymer manufacturing, and textile industries.

[0003] The mainstream industrial method for producing alkylene carbonates involves reacting alkylene oxides with carbon dioxide. This method effectively utilizes carbon dioxide, mitigating greenhouse gas emissions. The process employs a homogeneous catalytic system. However, homogeneous systems present challenges in separating high-concentration catalysts, leading to product decomposition due to catalyst residue and high costs associated with the final solid and liquid waste treatment. Therefore, higher demands are placed on the greenness and economic efficiency of alkylene carbonate production processes.

[0004] Compared to homogeneous catalytic systems, heterogeneous catalytic systems do not suffer from difficulties in catalyst-product separation or catalyst residue. Currently, heterogeneous catalytic systems under development include oxides, MOFs, carbon materials, and ionic liquids. Examples include MgO-Al₂O₃ metal compounds, the bifunctional porous metal-organic framework material UiO-67-IL, imidazole-type ionic liquid catalysts supported on chitosan, hydroxyimidazolium-type ionic liquids supported on ion exchange resins, and zinc halide catalysts supported on ion exchange resins. Among these, catalysts supported on ion exchange resins have been studied extensively.

[0005] Zhang et al. reported a hydroxyimidazolium-based ionic liquid, PS-HEIMBR, supported on an ion exchange resin (Catalysis Today 2009, 148, 361–367). When applied to an epoxy / CO2 system, this catalyst requires a very specific particle size. With 100 μm catalyst particles, after 4 hours of reaction at 120 °C and 2.5 MPa, the conversion of propylene oxide and the selectivity for propylene carbonate reached 99%, demonstrating high catalytic efficiency. However, unpolished 1 mm catalyst particles only converted 87% of the propylene oxide under the same conditions. Furthermore, the preparation of this catalyst requires the use of bromoethanol, increasing production costs and hindering industrial application.

[0006] CN105503608A discloses a halogen-type composite hydroxyimidazolium resin catalyst, in which nanomaterials such as carbon nanotubes and hydroxy halides are added during catalyst preparation to improve material performance. Under the action of this catalyst, after treatment at 120℃ and 2.0 MPa for 3 hours, the conversion rate of ethylene oxide can reach 98.6%, and the selectivity of ethylene carbonate can reach 99.7%. However, the nanomaterials and hydroxy halides used in the preparation also increase the production cost of the catalyst, and the catalyst's reproducibility is poor, with performance declining after 5 uses.

[0007] Xia et al. reported a system in Appl. Catal. A 2005, 279: 125-129, using chitosan supported with zinc halide as the main catalyst and 1-butyl-3-methylimidazolium bromide as the co-catalyst. Under conditions of 110 °C and 1.5 MPa, after 1 hour of reaction between propylene oxide and CO2, the selectivity of propylene carbonate reached over 99%, and the yield reached 95%. After adjusting the process parameters, the highest yield of propylene carbonate reached 97%. However, due to insufficient stability and strength of the catalytic system, after five repetitions, the yield of propylene carbonate decreased from 95% to 87%, which is not conducive to industrial-scale production.

[0008] DWPark et al. reported a 1-butyl-3-(3-triethoxysilane)propyl-imidazolium iodide catalytic system supported on carboxymethyl cellulose in Green Chem., 2012, 14, 2933-2940. Under conditions of 110 °C and 1.8 MPa, after 2 hours of reaction between propylene oxide and CO2, the selectivity for propylene carbonate reached over 99%, and the yield reached 98.6%, exhibiting high catalytic efficiency. However, this catalyst system also suffers from low catalyst strength and insufficient stability; after four repetitions, the product yield decreased from 98% to 71%.

[0009] LN He reported in Green Chem., 2005, 7, 518–523, that the reaction of propylene oxide with CO2 at 100°C and 8 MPa for 24 hours under the catalysis of conventional ion exchange resin D201 achieved a selectivity of 99.8% and a yield of 99.2%, demonstrating extremely high activity. After five repetitions, although the selectivity of propylene carbonate did not decrease significantly, the yield decreased to 94%.

[0010] It is evident that although heterogeneous catalytic systems, including ion exchange resin catalysts, have many advantages, they still have some shortcomings. Researching and developing a heterogeneous catalytic system with high stability and strength remains a hot topic in the research of epoxide / carbon dioxide addition catalysts. Summary of the Invention

[0011] The purpose of this invention is to overcome the problem of poor recyclability of existing cycloaddition catalysts, and to provide a cycloaddition catalyst, its preparation method and application, and a method for preparing cyclic carbonates. This cycloaddition catalyst exhibits superior catalytic activity and can be used continuously multiple times.

[0012] To achieve the above objectives, a first aspect of the present invention provides a cycloaddition catalyst, wherein the catalyst comprises a support formed by a shaped molecular sieve and an ion exchange resin supported on the support, and the catalyst has the structure shown in formula (1).

[0013]

[0014] In equation (1), As a carrier, It is a styrene copolymer segment, where R1 is alkyl or aryl, and X - It is an anion.

[0015] The second aspect of the present invention provides a method for preparing the catalyst described in the first aspect of the present invention, wherein the preparation method includes: (1) copolymerizing a support adsorbed with an oil phase; (2) subjecting the molecular sieve / resin balls obtained by copolymerization to halomethylation, imidazoleization, and ion exchange; wherein the oil phase contains styrene-based comonomers, crosslinking agents, and initiators.

[0016] The third aspect of the present invention provides the application of the cycloaddition catalyst described in the first aspect of the present invention in the preparation of cyclic carbonates.

[0017] A fourth aspect of the present invention provides a method for preparing cyclic carbonates, wherein the method comprises: cycloaddition reaction of an epoxide and carbon dioxide in the presence of the cycloaddition catalyst described in the first aspect of the present invention.

[0018] Through the above technical solution, the cycloaddition catalyst of the present invention belongs to the heterogeneous catalyst, which has high strength, is easy to separate after use, has high catalytic activity, and has high stability. The catalyst can be used continuously multiple times. For example, when used as a cycloaddition catalyst, it can obtain a high yield of cycloaddition product, and after the catalyst is recycled multiple times, a high yield of cycloaddition product can still be obtained. Detailed Implementation

[0019] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0020] In this invention, the term "alkyl" can refer to either branched alkyl or straight-chain alkyl, and there are no particular limitations.

[0021] In this invention, "room temperature" refers to 15-30°C.

[0022] In this invention, the "drying / baking" method is a conventional method in the art. The drying can be carried out under normal pressure or in a vacuum environment, for example, drying / baking at 80-110°C for 8-20 hours, or drying / baking at 50-70°C under vacuum for 10-15 hours. This invention does not have any special limitations on this, and those skilled in the art can choose according to their needs.

[0023] A first aspect of the present invention provides a cycloaddition catalyst, wherein the catalyst comprises a support formed by a shaped molecular sieve and an ion exchange resin supported on the support, and the catalyst has the structure shown in formula (1).

[0024]

[0025] In equation (1), As a carrier, It is a styrene copolymer segment, where R1 is alkyl or aryl, and X - It is an anion.

[0026] In this invention, it is understood that, The catalyst comprises an ion exchange resin supported on a carrier. The cycloaddition catalyst in this invention is a heterogeneous catalyst, exhibiting excellent catalytic performance and capable of repeated use. The inventors' research and analysis revealed that the molded molecular sieve has molecular sieve channels and molding channels. The ion exchange resin forms an interpenetrating structure with the molded molecular sieve, which better improves the network density of the interpenetrating structure. This allows the catalytic active sites of the catalyst to exert their catalytic effect more stably, and the ion exchange resin can be more stably loaded onto the carrier to exert its catalytic effect.

[0027] According to the present invention, it is understood that the styrene-based copolymer segment contains structural units derived from styrene-based comonomers. In some embodiments, the styrene-based copolymer segment contains structural unit a derived from styrene-based comonomers and structural unit b derived from a crosslinking agent. Using the aforementioned embodiments, the catalyst exhibits good catalytic activity and stability.

[0028] According to the present invention, the content of structural unit a and structural unit b is not particularly limited as long as the purpose of the present invention can be achieved. In some embodiments, based on the total mass of structural unit a and structural unit b, the content of structural unit a is 80-98% by mass, and the content of structural unit b is 2-20% by mass. Using the aforementioned embodiments, the catalyst has good catalytic activity and stability.

[0029] According to the present invention, the specific type of styrene-based comonomer providing structural unit a is not particularly limited as long as the purpose of the present invention can be achieved. In some embodiments, the structure of the styrene-based comonomer is as shown in formula (2):

[0030]

[0031] In equation (2), R 11 R is an alkyl group or hydrogen. 12 It is an alkyl group or hydrogen.

[0032] According to some preferred embodiments of the present invention, in formula (2), R 11 It is a C1-C6 alkyl group or hydrogen. Using the aforementioned embodiments, the catalyst exhibits better catalytic properties and stability.

[0033] According to some preferred embodiments of the present invention, in formula (2), R 12 It is a C1-C4 alkyl group or hydrogen. Using the aforementioned embodiments, the catalyst exhibits better catalytic properties and stability.

[0034] According to the present invention, those skilled in the art will understand that the segments in the ion-exchange chain are skeleton structures formed by copolymerization of styrene-based comonomers and crosslinking agents. As long as the purpose of the present invention can be achieved, the selection of the crosslinking agent is not limited. Any crosslinking agent containing two or more double bonds and capable of being initiated by styrene radicals can be used as the crosslinking agent of the present invention. In some preferred embodiments, the crosslinking agent is selected from one or more of ethylene glycol dimethacrylate, diallylbenzene, 1,1-(4-vinylphenyl)methane and divinylbenzene.

[0035] According to the present invention, in some preferred embodiments, R1 in formula (1) is a C1-C6 alkyl group, such as methyl, ethyl, propyl, butyl, pentyl, or hexyl, preferably a C1-C4 alkyl group. Using the aforementioned embodiments, the catalyst exhibits good catalytic activity and stability.

[0036] According to the present invention, in some embodiments, in formula (1), X -The ions are halide ions (e.g., chloride ions, bromide ions, iodide ions, etc.) and / or organic acid anions (e.g., acetate ions, formate ions, hydrogen oxalate ions, etc.). Using the aforementioned embodiments, the catalyst exhibits good catalytic activity and stability.

[0037] According to some preferred embodiments of the present invention, in formula (1), X - It is one or more of chloride ions, bromide ions, iodide ions, and formate ions. Using the aforementioned embodiments, the catalyst exhibits good catalytic activity and stability.

[0038] According to the present invention, it can be understood that when X - It can exist in a single ionic form, such as being entirely chloride ions, and can be obtained through complete ion exchange. X - It can also be two or more different ions, which can be obtained through partial ion exchange, making the anion have two or more forms, for example, in Cl. - If less than the theoretical amount of bromide ions is added to the catalyst, the final anion form will be Cl. - With B r- These two forms. For ease of preparation, X is used in all embodiments of this invention. - The advantages of the invention are illustrated by using a single ionic form as an example, but the invention is not limited thereto.

[0039] According to the present invention, the loading amount of ion exchange resin on the support is not particularly limited as long as the purpose of the present invention can be achieved. In some embodiments, the loading amount of the ion exchange resin is 10-55 wt%, preferably 15-45 wt%. By adopting the foregoing embodiments, the ion exchange resin and the support can better synergistically interact, and the catalyst has excellent catalytic activity and stability.

[0040] According to the present invention, in some embodiments, the specific surface area of ​​the catalyst is 30-500 m². 2 / g, preferably 50-200m 2 / g. Using the aforementioned embodiments, the catalyst possesses excellent active sites and maintains excellent catalytic activity even after multiple cycles.

[0041] According to the present invention, it is understood that the molded molecular sieve is a product formed by exchanging molecular sieves (i.e., molecular sieve powder) with optional molding aids through molding equipment, and optionally at high temperature. As long as the purpose of the present invention is achieved, the shape of the molded molecular sieve is not particularly limited. In some embodiments, the shape of the molded molecular sieve is selected from one or more of strip, spherical, and columnar shapes. Using the aforementioned embodiments, the ion exchange resin can form a more compact structure with the catalyst, resulting in better catalytic activity and stability of the catalyst.

[0042] According to the present invention, the particle size of the shaped molecular sieve is not particularly limited as long as the purpose of the present invention can be achieved. In some embodiments, the particle size of the shaped molecular sieve is 0.4-5 mm, preferably 1.3-2.4 mm. Using the aforementioned embodiments, the catalyst exhibits better catalytic activity.

[0043] According to the present invention, in some embodiments, the specific surface area of ​​the shaped molecular sieve is 300-1000 m². 2 / g, preferably 400-700m 2 / g. Using the aforementioned embodiments, the catalyst exhibits better catalytic activity and stability.

[0044] According to the present invention, in some embodiments, the compressive strength of the shaped molecular sieve is greater than or equal to 30 N. Using the aforementioned embodiments, the catalyst exhibits better catalytic activity and stability.

[0045] According to the present invention, in some embodiments, the molecular sieve in the shaped molecular sieve includes an aluminosilicate molecular sieve. Using the aforementioned embodiments, the catalyst exhibits excellent catalytic activity and stability.

[0046] According to the present invention, in some embodiments, the aluminosilicate molecular sieve is selected from one or more of type A molecular sieves, zeolite molecular sieves, type X molecular sieves, ZSM molecular sieves, and type Y molecular sieves. Using the aforementioned embodiments, the catalyst exhibits excellent catalytic activity and stability.

[0047] According to some preferred embodiments of the present invention, the aluminosilicate molecular sieve is a type A molecular sieve. Using the aforementioned embodiments, the catalyst exhibits excellent catalytic activity and stability.

[0048] According to the present invention, in some preferred embodiments, the type A molecular sieve is selected from one or more of type 3A, type 4A, and type 5A molecular sieves. Using the aforementioned embodiments, the catalyst exhibits excellent catalytic activity and stability.

[0049] The second aspect of the present invention provides a method for preparing the catalyst described in the first aspect of the present invention, wherein the preparation method includes: (1) copolymerizing a support adsorbed with an oil phase; (2) subjecting the molecular sieve / resin balls obtained by copolymerization to halomethylation, imidazoleization, and ion exchange; wherein the oil phase contains styrene-based comonomers, crosslinking agents, and initiators.

[0050] In this invention, the molded molecular sieve support has channels, and all or most of the styrene comonomer, crosslinking agent, and initiator are adsorbed in the channels of the support. Then, a copolymerization reaction is carried out to form styrene comonomer segments to obtain molecular sieve / resin balls. Subsequently, the molecular sieve / resin balls undergo a series of functionalization treatments to form a catalyst including an ion exchange resin supported on the support. The ion exchange resin and the support (molded molecular sieve) can form a tight and stable interpenetrating structure with a large number of catalytic active sites. The prepared catalyst has excellent catalytic activity and can be recycled multiple times.

[0051] According to the present invention, the appropriate amount of oil phase adsorption can be selected according to the loading of the ion exchange resin. The oil phase needs a certain amount of time to adsorb onto the carrier. As long as the purpose of the present invention can be achieved, there is no particular limitation on the way the oil phase is adsorbed onto the carrier. In some embodiments, the method of obtaining the carrier adsorbed with the oil phase includes: immersing the carrier in the oil phase and then filtering to obtain the carrier adsorbed with the oil phase.

[0052] According to some preferred embodiments of the present invention, the amount of the styrene-based comonomer is 35-60 wt%, the amount of the crosslinking agent is 2-10 wt%, the amount of the initiator is 0.1-3 wt%, and the amount of the support is 30-60 wt%, based on the total mass of the oil phase and the support. The catalyst prepared using the foregoing embodiments exhibits excellent stability and catalytic activity.

[0053] According to the present invention, the soaking conditions are not particularly limited as long as the purpose of the present invention can be achieved. In order to allow the oil phase to be absorbed by the carrier and react, in some embodiments, the soaking conditions include: room temperature.

[0054] According to the present invention, in some embodiments, the soaking conditions include a soaking time of 6-36 hours.

[0055] According to some preferred embodiments of the present invention, in step (1), the conditions of the copolymerization reaction include: a reaction temperature of 80-100°C.

[0056] According to some preferred embodiments of the present invention, in step (1), the conditions of the copolymerization reaction include a reaction time of 4-12 hours.

[0057] According to the present invention, it is understood that the product of the copolymerization reaction is a molecular sieve / resin ball, but there may be some residual monomer raw materials in the product. In order to obtain a relatively pure molecular sieve / resin ball, those skilled in the art can choose a suitable post-processing method, such as washing and then drying. Specifically, methanol is used for washing.

[0058] According to the present invention, those skilled in the art can select a halomethylation method based on the present invention. In some embodiments, the halomethylation method includes: a molecular sieve / resin ball undergoing a halomethylation reaction with a halomethylating agent in the presence of a Lewis acid catalyst, followed by a first purification separation. The catalyst prepared using the foregoing embodiments exhibits good catalytic activity.

[0059] According to the present invention, the amount of Lewis acid catalyst and halomethylating agent can be selected as needed. In some embodiments, the amount of Lewis acid catalyst is 2-15 wt% of the molecular sieve / resin ball mass; in some embodiments, the ratio of molecular sieve / resin ball to halomethylating agent is 1 g to (1-5) mL.

[0060] According to the present invention, in some embodiments, the Lewis acid catalyst is at least one halide selected from Zn, Al, Ti, Sb, and Zr, such as at least one selected from ZnCl2, AlCl3, TiCl4, SbF5, and ZrCl4.

[0061] According to the present invention, in some embodiments, the halomethylating agent is a halomethyl C1-C4 alkyl ether, such as chloromethyl methyl ether, bromomethyl methyl ether, chloromethyl ethyl ether, bromomethyl ethyl ether, chloromethyl propyl ether, bromomethyl propyl ether, chloromethyl butyl ether, and bromomethyl butyl ether.

[0062] According to the present invention, in some embodiments, the conditions for the halomethylation reaction include a reaction temperature of 50-60°C.

[0063] According to the present invention, in some embodiments, the conditions for the halomethylation reaction include a reaction time of 5-15 hours.

[0064] According to the present invention, some residual raw materials may remain after the halomethylation reaction. After the halomethylation reaction, a first purification separation can be performed as needed to obtain the halomethylated product (molecular sieve / resin halogen ball). Those skilled in the art can select the first purification separation method as needed, for example, after the halomethylation reaction, filter out the halogenation mother liquor, then wash repeatedly with methanol, and finally dry to obtain the halomethylated product (molecular sieve / resin halogen ball).

[0065] According to the present invention, it is understood that the product after halomethylation is a molecular sieve / resin halogen ball. In order to ensure the smooth progress of subsequent imidazoleization, imidazoleization is carried out in the presence of a solvent as needed. In some embodiments, the imidazoleization method includes: in the presence of a solvent, the product after halomethylation is reacted with an imidazole compound represented by formula (3) to undergo an imidazoleization reaction, followed by a second purification and separation.

[0066]

[0067] In equation (3), the definition of R1 is the same as in equation (1).

[0068] According to the present invention, in some embodiments, the conditions for the imidazole reaction include: reaction under reflux conditions.

[0069] According to the present invention, in some embodiments, the conditions for the imidazole reaction include a reaction time of 10-30 hours.

[0070] According to the present invention, some residual raw materials may remain after the imidazole reaction. A second purification and separation is required in the imidazole reaction to obtain the imidazole product (molecular sieve / resin imidazole balls). Those skilled in the art can select the second purification and separation method as needed. For example, after the imidazole reaction, the reaction solution can be removed by filtration, and then washed successively with ethyl acetate, 0.05-0.15 mol / L HCl, and water, and finally dried to obtain the imidazole product (molecular sieve / resin imidazole balls).

[0071] According to the present invention, in some embodiments, the ion exchange method includes: the imidazole-treated product (molecular sieve / resin imidazole beads) and the anion X - An ion exchange reaction was carried out with an aqueous solution of an alkali metal salt, followed by washing until neutral and drying, wherein X - Same as the definition in equation (1); specifically, during ion exchange, molecular sieve / resin imidazole balls can be packed into the exchange column, and then X anions are used. - Ion exchange is performed using an aqueous solution of an alkali metal salt; the anion is X. - There is no specific limit to the amount of alkali metal salt aqueous solution used; exchange can proceed until saturation is achieved. For example, the anion concentration of molecular sieve / resin imidazole spheres is X. - The volume ratio of the alkali metal salt aqueous solution is 1:(8-30).

[0072] According to the present invention, in some embodiments, the solubility of the alkali metal salt aqueous solution is 0.1-1 mol / L.

[0073] According to the present invention, the anions that can be listed are X. - Alkali metal salts include NaX, KX, FeX3, and CaX2.

[0074] The third aspect of the present invention provides the application of the cycloaddition catalyst described in the first aspect of the present invention in the preparation of cyclic carbonates.

[0075] In this invention, when using the cycloaddition catalyst of this invention to prepare cyclic carbonates, not only can a high yield of cyclic carbonate products be obtained, but the cycloaddition catalyst can also produce cyclic carbonate products even after repeated use.

[0076] A fourth aspect of the present invention provides a method for preparing cyclic carbonates, wherein the method comprises: cycloaddition reaction of an epoxide and carbon dioxide in the presence of the cycloaddition catalyst described in the first aspect of the present invention.

[0077] In this invention, in the presence of the specific cycloaddition catalyst of this invention, epoxides and carbon dioxide can undergo a better cycloaddition reaction to obtain a high yield of cyclic carbonates, and the cycloaddition catalyst can be reused multiple times to carry out cycloaddition reactions to obtain a high yield of cyclic carbonates.

[0078] According to the present invention, a corresponding epoxy compound can be selected as a raw material according to the type of cyclic carbonate required. In some embodiments, the structure of the epoxy compound is shown in formula (I):

[0079]

[0080] In formula (I), R is hydrogen, alkyl, or phenyl.

[0081] According to some preferred embodiments of the present invention, in formula (I), R is hydrogen, C1-C3 alkyl or phenyl.

[0082] According to the present invention, epoxide compounds that can be exemplified include ethylene oxide, propylene oxide, butane oxide, or styrene oxide.

[0083] According to the present invention, in some embodiments, the conditions for the cycloaddition reaction include: the mass ratio of the cycloaddition catalyst to the epoxide is (0.001-1):1, preferably (0.1-0.3):1.

[0084] According to the present invention, in some embodiments, the conditions for the cycloaddition reaction include: a reaction temperature of 60-180°C, preferably 100-160°C.

[0085] According to the present invention, in some embodiments, the conditions for the cycloaddition reaction include: a reaction pressure of 0.1-10 MPa, preferably 2-5 MPa.

[0086] According to the present invention, in some embodiments, the conditions for the cycloaddition reaction include a reaction time of 1-12 hours.

[0087] The present invention will be described in detail below through embodiments. In the following embodiments and comparative examples:

[0088] The prepared cycloaddition catalysts were used in the cycloaddition reactions of propylene oxide and carbon dioxide, respectively, and the experiments were as follows:

[0089] Under the protection of high-purity nitrogen, 40.0 g of propylene oxide and 5 g of cycloaddition catalyst were added to a 200 mL autoclave, 1.0 MPa of CO2 was introduced, the temperature was raised to 120 °C, and then CO2 was introduced to maintain the reaction pressure at 3.0 MPa. After reacting for 4 hours, the catalyst was removed by filtration and the reaction was tested.

[0090] Example 1

[0091] In a 500ml flask, add 150g styrene, 12g divinylbenzene, and 3g benzoyl peroxide. Stir for 60 minutes, then add 100g of spherical 5A molecular sieve (particle size 2.2mm, specific surface area 390m²). 2 / g, compressive strength of 65N), soaked for 24 hours; then filter the oil phase to obtain molecular sieve with adsorbed oil phase, place it at 90℃ for 10 hours, then rinse with methanol and dry to obtain molecular sieve / resin ball;

[0092] In a 500 mL three-necked flask, add 60 g of molecular sieve / resin balls and 200 mL of chloromethyl ether, let stand at room temperature for 2 hours, then add 8 g of zinc chloride as a catalyst and start stirring. Gradually raise the temperature to 60 °C and react for 10 hours. After chloromethylation is completed, cool to room temperature, filter out the chlorination mother liquor, wash with methanol, and dry at 100 °C for 8 hours to obtain molecular sieve / resin chlorination balls.

[0093] Add 60 g of molecular sieve / resin imidazole balls, 130 ml of N-methylimidazole, and 200 ml of N,N-dimethylformamide to a 500 mL three-necked flask. After reacting under reflux for 24 hours, cool to room temperature, filter to remove the reaction solution, and then wash with ethyl acetate, 0.1 mol / L HCl, and deionized water in sequence. Then dry at 80 °C for 16 hours to obtain molecular sieve / resin imidazole balls.

[0094] In an exchange column, 50 mL of molecular sieve / resin imidazole beads were added, and the exchange was carried out with 500 mL of 0.5 mol / L NaBr deionized water solution. The solution was then washed with deionized water until it was neutral, and after vacuum drying, the cycloaddition catalyst was obtained, denoted as Cat-A1.

[0095] The structure of the cycloaddition catalyst is as follows:

[0096] It is a spherical 5A type molecular sieve. It is a styrene-based copolymer matrix;

[0097] Specific surface area: 58m² 2 / g;

[0098] The loading of the ion exchange resin is 20 wt%.

[0099] The cycloaddition reaction of the primary reaction with carbon dioxide was carried out using a cycloaddition catalyst, and the experimental results are shown in Table 1.

[0100] The catalyst after the cycloaddition reaction was filtered, and then the cycloaddition reaction of propylene oxide and carbon dioxide was carried out according to the cycloaddition reaction, resulting in the cycloaddition catalyst being recycled twice. In this way, the catalytic reaction of carbon oxide was carried out for 5 cycles (the cycloaddition catalyst for each cycle was denoted as Cat-A1, Cat-A1-2, Cat-A1-3, Cat-A1-4, and Cat-A1-5, respectively). The experimental results are shown in Table 1.

[0101] Example 2

[0102] In a 500ml flask, add 150g styrene, 18g divinylbenzene, and 4g benzoyl peroxide. After stirring for 1 hour, add 100g of columnar 3A molecular sieve (particle size 1.5mm; specific surface area 500m²). 2 / g; compressive strength of 80N), soaked at room temperature for 15 hours, then filtered to obtain molecular sieve with adsorbed oil phase, placed at 90℃ for 10 hours, then washed with methanol and dried to obtain molecular sieve / resin;

[0103] In a 500 mL three-necked flask, add 100 g of molecular sieve / resin and 300 mL of chloromethyl ether, let stand at room temperature for 2 hours, then add 8 g of zinc chloride as a catalyst and start stirring. Gradually raise the temperature to 60 °C and react for 12 hours. After the reaction is complete, cool to room temperature, filter out the chlorination mother liquor, wash with methanol, and dry at 100 °C for 8 hours to obtain molecular sieve / chlorination resin.

[0104] Add 90 g of molecular sieve / resin imidazole balls, 200 ml of N-methylimidazole, and 200 ml of N,N-dimethylformamide to a 500 mL three-necked flask. After reacting under reflux for 24 hours, cool to room temperature, filter to remove the reaction solution, and then wash with ethyl acetate, 0.1 mol / L HCl, and deionized water in sequence. Then dry at 80 °C for 16 hours to obtain molecular sieve / resin imidazole balls.

[0105] In an exchange column, 100 mL of molecular sieve / resin imidazole beads were added, and the exchange was carried out with 2000 mL of 0.25 mol / L NaBr deionized water solution. The solution was then washed with deionized water until it was neutral, and after vacuum drying, the cycloaddition catalyst was obtained, denoted as Cat-A2.

[0106] The structure of the cycloaddition catalyst is as follows:

[0107] It is a columnar 3A type molecular sieve. It is a styrene-based copolymer matrix;

[0108] Specific surface area: 150m² 2 / g

[0109] The loading of the ion exchange resin is 30 wt%.

[0110] The cycloaddition reaction of propylene oxide and carbon dioxide was carried out using a cycloaddition catalyst, and the experimental results are shown in Table 1.

[0111] Example 3

[0112] In a 500ml flask, add 150g styrene, 6g diallylphenyl, and 5g benzoyl peroxide. After stirring for 1 hour, add 100g of spherical 4A molecular sieve (particle size 3.2mm; specific surface area 900m²). 2 / g; compressive strength of 85N), soaked at room temperature for 6 hours, then filtered to obtain molecular sieve with adsorbed oil phase, placed at 90℃ for 10 hours, then washed with methanol and dried to obtain molecular sieve / resin;

[0113] In a 500 mL three-necked flask, add 100 g of molecular sieve / resin and 300 mL of chloromethyl ethyl ether, let stand at room temperature for 2 hours, then add 3 g of zinc chloride as a catalyst and start stirring. Gradually raise the temperature to 50 °C and react for 12 hours. After the reaction is complete, cool to room temperature, filter out the chlorination mother liquor, wash repeatedly with methanol, and dry at 100 °C for 8 hours to obtain molecular sieve / chlorination resin.

[0114] Add 90 g of molecular sieve / resin imidazole balls, 150 ml of N-methylimidazole, and 200 ml of N,N-dimethylformamide to a 500 mL three-necked flask. After reacting under reflux for 24 hours, cool to room temperature, filter to remove the reaction solution, and then wash with ethyl acetate, 0.1 mol / L HCl, and deionized water in sequence. Finally, dry under vacuum at 50 °C for 10 hours to obtain molecular sieve / resin imidazole balls.

[0115] In an exchange column, 100 mL of molecular sieve / resin imidazole beads were added, and the exchange was carried out with 2000 mL of 0.25 mol / L NaBr deionized water solution. The solution was then washed with deionized water until it was neutral, and after vacuum drying, the cycloaddition catalyst was obtained, denoted as Cat-A3.

[0116] The structure of the cycloaddition catalyst is as follows:

[0117] It is a spherical 4A type molecular sieve. It is a styrene-based copolymer matrix;

[0118] Specific surface area: 253 m² 2 / g;

[0119] The loading of the ion exchange resin was 17 wt%.

[0120] The cycloaddition reaction of propylene oxide and carbon dioxide was carried out using a cycloaddition catalyst, and the experimental results are shown in Table 1.

[0121] Example 4

[0122] The method according to Example 1 differs in that:

[0123] The imidazole reagent was replaced with N-propylimidazolium instead of N-methylimidazolium, with all other conditions remaining the same. The resulting cycloaddition catalyst is designated Cat-A4.

[0124] The structure of the cycloaddition catalyst is as follows:

[0125] It is a spherical 5A type molecular sieve. It is a styrene-based copolymer matrix;

[0126] Specific surface area: 53m² 2 / g

[0127] The loading of the ion exchange resin is 25 wt%.

[0128] The cycloaddition reaction of propylene oxide and carbon dioxide was carried out using a cycloaddition catalyst, and the experimental results are shown in Table 1.

[0129] Example 5

[0130] The method of Example 2 is followed, except that α-methylstyrene is used instead of styrene and ethylene glycol dimethacrylate is used instead of divinylbenzene, while other conditions are the same. The resulting cycloaddition catalyst is denoted as Cat-A5.

[0131] The structure of the cycloaddition catalyst is as follows:

[0132] It is a columnar 3A type molecular sieve. It is a styrene-based copolymer matrix;

[0133] Specific surface area: 140 m² 2 / g

[0134] The loading of the ion exchange resin was 34 wt%.

[0135] The cycloaddition reaction of propylene oxide and carbon dioxide was carried out using a cycloaddition catalyst, and the experimental results are shown in Table 1.

[0136] Example 6

[0137] The method of Example 3 was followed, except that phenylimidazole was used instead of methylimidazole, while the other conditions remained the same. The resulting cycloaddition catalyst was denoted as Cat-A6.

[0138] The structure of the cycloaddition catalyst is as follows:

[0139] It is a spherical 4A type molecular sieve. It is a styrene-based copolymer matrix;

[0140] Specific surface area: 185 m² 2 / g

[0141] The loading of the ion exchange resin is 30 wt%.

[0142] The cycloaddition reaction of propylene oxide and carbon dioxide was carried out using a cycloaddition catalyst, and the experimental results are shown in Table 1.

[0143] Example 7

[0144] The method is the same as in Example 1, except that spherical ZSM-5 molecular sieves (particle size 2-3 mm; specific surface area 360 m²) are used. 2 / g; compressive strength of 70) replaced the spherical 5A molecular sieve, and the other conditions were the same. The final cycloaddition catalyst was denoted as Cat-A7.

[0145] The structure of the cycloaddition catalyst is as follows:

[0146] It is a spherical ZSM-5 molecular sieve. It is a styrene-based copolymer matrix;

[0147] Specific surface area: 63m² 2 / g;

[0148] The loading of the ion exchange resin was 18 wt%.

[0149] Comparative Example 1

[0150] The catalyst intermediate was prepared according to the method of Example 1, except that powdered molecular sieves were used instead of formed molecular sieves, while the other conditions remained the same.

[0151] The catalyst intermediate was spheroidized into a hydrated catalyst with a diameter of 2 mm, denoted as Cat-B1.

[0152] The final catalyst is designated Cat-B1.

[0153] The specific surface area of ​​the cycloaddition catalyst is 45 m². 2 / g;

[0154] The loading of the ion exchange resin was 16 wt%.

[0155] The cycloaddition reaction of the primary reaction with carbon dioxide was carried out using a cycloaddition catalyst, and the experimental results are shown in Table 1.

[0156] Table 1

[0157]

[0158] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A cycloaddition catalyst, characterized in that, The catalyst comprises a support formed by a shaped molecular sieve and an ion exchange resin supported on the support, and the catalyst has the structure shown in formula (1). Equation (1), The carrier, It is a styrene copolymer segment, where R1 is alkyl or aryl, and X - It is an anion; The loading of the ion exchange resin is 10-55 wt%; The specific surface area of ​​the shaped molecular sieve is 300-1000 m². 2 / g, The compressive strength of the shaped molecular sieve is greater than or equal to 30N.

2. The catalyst according to claim 1, wherein, The styrene copolymer segment contains structural unit a from the styrene comonomer and structural unit b from the crosslinking agent.

3. The catalyst according to claim 2, wherein, In the styrene copolymer segments, based on the total mass of structural unit a and structural unit b, the content of structural unit a is 80-98% by mass, and the content of structural unit b is 2-20% by mass; and / or The structure of the styrene comonomer is shown in formula (2): Equation (2), In equation (2), R 11 R is an alkyl group or hydrogen. 12 It is an alkyl group or hydrogen; The crosslinking agent is selected from those containing two or more double bonds and capable of initiating crosslinking with styrene radicals.

4. The catalyst according to claim 3, wherein, In equation (2), R 11 C1-C6 alkyl or hydrogen and / or R 12 It is C1-C4 alkyl or hydrogen; The crosslinking agent is one or more of dimethacrylate, diallylbenzene, 1,1-(4-vinylphenyl)methane, and divinylbenzene.

5. The catalyst according to claim 1, wherein, In formula (1), R1 is a C1-C6 alkyl group; and / or In equation (1), X - It is a halide ion and / or anion of organic acid anions; and / or The loading of the ion exchange resin is 15-45 wt%; and / or The catalyst has a specific surface area of ​​30-500 m². 2 / g.

6. The catalyst according to claim 5, wherein, In formula (1), R1 is a C1-C4 alkyl group; and / or In equation (1), X - It is one or more of chloride ions, bromide ions, iodide ions, and formate ions; and / or The catalyst has a specific surface area of ​​50-200 m². 2 / g.

7. The catalyst according to claim 1, wherein, The shape of the shaped molecular sieve is selected from one or more of strip, spherical, and columnar shapes; and / or The particle size of the shaped molecular sieve is 0.4-5 mm; and / or The specific surface area of ​​the shaped molecular sieve is 400-700 m². 2 / g; and / or The molecular sieves in the molded molecular sieves include aluminosilicate molecular sieves.

8. The catalyst according to claim 7, wherein, The particle size of the shaped molecular sieve is 1.3-2.4 mm; and / or The aluminosilicate molecular sieve is selected from one or more of type A molecular sieve, zeolite molecular sieve, type X molecular sieve, type ZSM molecular sieve and type Y molecular sieve.

9. The catalyst according to claim 8, wherein, The aluminosilicate molecular sieve is a type A molecular sieve.

10. The catalyst according to claim 9, wherein, The type A molecular sieve is selected from one or more of type 3A molecular sieve, type 4A molecular sieve, and type 5A molecular sieve.

11. A method for preparing the catalyst according to any one of claims 1-10, characterized in that, The preparation method includes: (1) The carrier adsorbed with oil phase undergoes copolymerization reaction; (2) The molecular sieves / resin balls obtained by copolymerization are subjected to halomethylation, imidazoleization, and ion exchange; The oil phase contains styrene-based comonomers, crosslinking agents, and initiators.

12. The preparation method according to claim 11, wherein, The method for obtaining the carrier adsorbed with the oil phase includes: immersing the carrier in the oil phase, followed by filtration to obtain the carrier adsorbed with the oil phase; and / or In step (1), the conditions for the copolymerization reaction include: a reaction temperature of 80-100℃; and / or a reaction time of 4-12 hours.

13. The preparation method according to claim 12, wherein, In the method for obtaining the carrier adsorbed with the oil phase, the amount of the styrene comonomer is 35-60 wt%, the amount of the crosslinking agent is 2-10 wt%, the amount of the initiator is 0.1-3 wt%, and the amount of the carrier is 30-60 wt%, based on the total mass of the oil phase and the carrier; and / or The soaking conditions include: room temperature and / or soaking time of 6-36 hours.

14. The preparation method according to claim 11, wherein, The halomethylation method comprises: a halomethylation reaction of molecular sieves / resin beads with a halomethylating agent in the presence of a Lewis acid catalyst, followed by a first purification separation; and / or The imidazoleization method comprises: in the presence of a solvent, reacting the halomethylated product with an imidazole compound of formula (3) to undergo an imidazoleization reaction, followed by a second purification and separation. Equation (3) In equation (3), the definition of R1 is the same as in equation (1); and / or The ion exchange method includes: the imidazole-treated product and the anion being X. - An ion exchange reaction was carried out with an aqueous solution of an alkali metal salt, followed by washing until neutral and drying; wherein, X - Same as the definition in equation (1).

15. The preparation method according to claim 14, wherein, The conditions for the halomethylation reaction include: a reaction temperature of 50-60°C and / or a reaction time of 5-15 hours; and / or The conditions for the imidazole reaction include: reaction under reflux and / or a reaction time of 10-30 hours.

16. The use of the cycloaddition catalyst according to any one of claims 1-10 in the preparation of cyclic carbonates.

17. A method for preparing a cyclic carbonate, characterized in that, The preparation method includes: cycloaddition reaction of an epoxide and carbon dioxide in the presence of the cycloaddition catalyst described in any one of claims 1-10.

18. The preparation method according to claim 17, wherein, The structure of the epoxy compound is shown in formula (I): Formula (I), In formula (I), R is hydrogen, alkyl or phenyl.

19. The preparation method according to claim 18, wherein, R is hydrogen, C1-C3 alkyl, or phenyl.

20. The preparation method according to claim 17, wherein, The conditions for the cycloaddition reaction include: The mass ratio of the cycloaddition catalyst to the epoxide is (0.001-1):1; and / or The reaction temperature is 60-180℃; and / or The reaction pressure is 0.1-10 MPa; and / or The reaction time is 1-12 hours.

21. The preparation method according to claim 20, wherein, The conditions for the cycloaddition reaction include: The mass ratio of the cycloaddition catalyst to the epoxide is (0.1-0.3):1; and / or The reaction temperature is 100-160℃; and / or The reaction pressure is 2-5 MPa.

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